1. Field
Some example embodiments relate to nitride semiconductor devices and methods of manufacturing the nitride semiconductor devices, and more particularly, high-quality nitride semiconductor devices and methods of manufacturing the high-quality nitride semiconductor devices.
2. Description of the Related Art
The electronics industry using nitride semiconductors has drawn attention as one suitable for the development and growth of green industries. In particular, gallium nitride (GaN), a nitride semiconductor, is widely used in a light-emitting diode (LED) display device and a back-light device. In addition, an LED has relatively low power consumption and a relatively long lifetime, compared to conventional light bulbs or fluorescent lamps, and thus, the LED device is widely being used as a general lighting device instead of light bulbs or fluorescent lamps. GaN is widely used to manufacture a blue LED from among red, green, and blue LEDs, which are essential elements of high power electronic component devices including an LED, because a blue LED using GaN is more desirable in terms of brightness, lifespan, and internal quantum efficiency, compared to conventional blue LEDs using a semiconductor material, for example, zinc selenide (ZnSe), due to improved physical and chemical characteristics of GaN. Also, since GaN has a direct transition band gap structure and the band gap is adjustable in a range from about 1.9 eV to about 6.2 eV by using an indium (In) or aluminum (Al) alloy, semiconductor layers emitting green, blue, and white light may be manufactured by using GaN. That is, since an emission wavelength may be adjusted by the adjustment of the band gap, characteristics of a material may be customized to specific device characteristics.
For example, since a white LED that may replace a blue LED useful for optical recording and light bulbs may be made by using GaN, GaN is useful in light devices. Also, since GaN has a relatively high breakdown voltage and is stable at a relatively high temperature, GaN is useful in various fields such as high power devices and high temperature electronic devices. For example, GaN may be applied to a large electric board using a full color display, a traffic light, a light source of an optical recording medium, and a high power transistor of a vehicle engine.